Device and method for suturing of internal puncture sites

ABSTRACT

A suture applying device comprises a shaft having a nose piece attached at its distal end. The shaft and the nose piece are separated by a transition region, and a needle entry lumen in the shaft permits a flexible needle to be introduced in the distal direction. The needle is able to cross the transition region and penetrate tissue held therein and enter into a return lumen in the nose piece. The return lumen is U-shaped and acts to bend the flexible needle as it is advanced. In this way, the needle passes from the nose piece through the transition region in a proximal direction, and is able to pass through tissue within the transition region generally on the opposite side of a tissue puncture from the first suture passage. The needle then exits from the device, permitting the suture attached to the needle to be drawn fully through the device. The suture may then be tied in order to close and seal the tissue penetration.

This is a Continuation of application Ser. No. 08/148,809, filed Nov. 8,1993 U.S. Pat. No. 5,527,827.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to devices and methods for thepercutaneous closure of body lumens. More particularly, the presentinvention relates to devices and methods for the percutaneous closure ofarterial and venous puncture sites, which are usually accessible onlythrough a tissue tract.

A number of diagnostic and interventional vascular procedures are nowperformed transluminally, where a catheter is introduced to the vascularsystem at a convenient access location and guided through the vascularsystem to a target location using established techniques. Suchprocedures require vascular access which is usually established using anintroducer sheath according to the well known Seldinger technique, asdescribed, for example, in William Grossman's "Cardiac Catheterizationand Angiography," 3rd Ed., Lea and Febiger, Philadelphia, 1986,incorporated herein by reference.

When vascular access is no longer required, the introducer sheath mustbe removed and bleeding at the puncture site stopped. One commonapproach for achieving hemostasis (the cessation of bleeding) is toapply external force adjacent to and upstream from the puncture site,typically by manual or "digital" compression. This approach suffers froma number of disadvantages. It is time-consuming, frequently requiringone-half hour or more of compression before hemostasis is assured. It isuncomfortable for the patient and frequently requires administeringanalgesics to be tolerable. Moreover, the application of excessivepressure can at times totally occlude the underlying blood vessel,resulting in ischemia and/or thrombosis. Following manual compressionthe patient is required to remain recumbent for at least six and attimes as long as eighteen hours under close observation to assurecontinued hemostasis. During this time renewed bleeding may occurresulting in bleeding through the tract, hematoma, and/or pseudoaneurismformation as well as arteriovenous fistula formation. Thesecomplications may require blood transfusion and/or surgicalintervention. The incidence of these complications increases when thesheath size is increased and when the patient is anticoagulated. It isclear that the standard technique for arterial closure can be risky andis expensive and onerous to the patient. While the risk of suchconditions can be reduced by using highly trained individuals, such useis both expensive and inefficient.

To overcome the problems associated with manual compression, the use ofbioabsorbable fasteners to stop bleeding has been proposed by severalgroups. Generally, these approaches rely on the placement of athrombogenic and bioabsorbable material, such as collagen, at thesuperficial arterial wall over the puncture site. While potentiallyeffective, this approach suffers from a number of problems. It can bedifficult to properly locate the interface of the overlying tissue andthe adventitial surface of the blood vessel, and locating the fastenertoo far from that surface can result in failure to provide hemostasisand subsequent hematoma and/or pseudo aneurism formation. Conversely, ifthe fastener intrudes into the arterial lumen, intravascular clotsand/or collagen pieces with thrombus attached can form and embolizedownstream causing vascular occlusion. Also, thrombus formation on thesurface of a fastener protruding into the lumen can cause a stenosiswhich can obstruct normal blood flow. Other possible complicationsinclude infection as well as adverse reactions to the collagen implant.

For these reasons, it would be desirable to provide improved devices andmethods to close and seal body lumen puncture sites. It would beparticularly desirable to provide percutaneous devices and methods forsuturing the puncture sites required for percutaneous vascularprocedures.

2. Description of the Background Art

Devices capable of delivering needles to various tissue locations aredescribed in the following patents and patent applications: U.S. Pat.Nos. 4,493,323 and 659,422; European patent application 140 557; andU.S.S.R patent applications 1174-036-A and 1093-329-A. Other suturingand ligating devices are described in U.S. Pat. Nos. 3,665,926;2,959,172; and 2,646,045. Devices for sealing percutaneous vascularpenetrations using various plug and fastener structures are described inU.S. Pat. Nos. 5,222,974; 5,192,302; 5,061,274; 5,021,059; 4,929,246;4,890,612; 4,852,568; 4,744,364; 4,587,969; and 3,939,820. Collagenfastener sealing devices are under commercial development by DatascopeCorp., Montvale, N.J., and Kensey Nash Corporation, Exton, Pa. U.S. Pat.No. 4,161,951, describes a needle driver to facilitate surgicalsuturing. U.S. Pat. No. 4,317,445, discloses a catheter having an axiallumen which provides an indication of blood flow when the catheter hasbeen successfully introduced to the vascular system. A brochure entitled"Innovation Through Progress" published by REMA-Medizintechnik GmbH,Durbheim-Tuttlingen, Germany, describes a suturing device which carriesa pair of needles with a length of suture extending therebetween at itsdistal end. Features of the REMA-Medizintechnik suturing device appearto be described in DE 42 10 724. A device and method for the suturing ofvascular penetration sites are described in copending application Ser.No. 07/989,611, commonly assigned with the present application.

SUMMARY OF THE INVENTION

The present invention provides devices and methods for suturing tissuepenetrations and puncture sites and is particularly useful for thesuturing of puncture sites distal to a tissue tract, such as puncturesformed in blood vessels to provide vascular access. Devices according tothe present invention will comprise a needle-guiding device including ashaft having a proximal end and a distal end and will define a needlepath having an entry segment, a return segment, and an exit segment.Using such devices, elongate flexible needles may be guided throughtissue on either side of a puncture site by pushing on the needle fromthe entry segment. The needle will then pass through tissue captured ina gap or transition region between the entry segment and the returnsegment. The needle is resiliently flexed (elastically deformed) to turnback on itself as it passes through the return segment of the needlepath and is thus directed proximally into the exit segment. The needlethus also passes through tissue captured in the gap between the returnsegment and the exit segment, permitting suture to be drawn by theneedle through opposed sides of the puncture site. The suture may thenbe tied off to close the puncture in a conventional manner.

According to a first aspect of the method of the present invention, theelongate flexible needle is provided and pushed inwardly so that itsdistal tip penetrates through an anterior surface of the wall of a bodylumen adjacent a puncture site. The flexible needle is then resilientlyflexed (elastically deformed) as it travels within the interior of thebody lumen so that the distal tip will penetrate proximally (outwardly)through a posterior surface of the luminal wall adjacent the puncturesite. As it emerges from the device, the needle straightens and may bepulled outwardly to draw suture through the needle penetrations thusformed on opposite sides of the puncture, and the suture tied off toclose the puncture site.

According to a second aspect of the method of the present invention,both the elongate flexible needle and a needle-guiding device areprovided. The needle-guiding device defines the needle path having anentry segment, a return segment, and an exit segment. The needle-guidingdevice is first introduced through a tissue tract so that a gap betweenthe entry/exit segments and the return segment lies at the puncturesite. After the needle-guiding device is in place, the flexible needlemay be pushed through the entry segment of the needle path so that theneedle first passes through tissue adjacent the puncture site and intothe return segment of the needle path. The needle is then turned as itadvances through the return segment so that it passes outwardly throughtissue on the other side of the puncture site and then into the exitsegment. The needle is pushed sufficiently far so that the distal end ofthe needle emerges from the exit segment of the needle path where it maybe manually grasped and pulled from the needle-guiding device. Thesuture is then released from the device, the device withdrawn, and thesuture tied to close the puncture site.

In a first aspect of the device of the present invention, the suturingdevice comprises a needle-guiding device including a shaft having aproximal end, a distal end, an entry lumen, and an exit lumen. A nosepiece is attached to the distal end of the shaft and includes a returnlumen disposed to receive the flexible needle from the entry lumen andto turn the needle to enter the exit lumen as the needle is advancedfrom the entry lumen. A gap between the shaft and the nose piecereceives the tissue to be sutured and exposes the tissue to passage ofthe suturing needle.

Typically, the nose piece will be elongated with a tapered distal tipand will have a circular cross-section having a maximum peripherallength which is generally equal to that of a transition region whichdefines a tissue-receiving gap between the nose piece and the shaft. Ina preferred embodiment, the nose piece will be fixed relative to theshaft. In an alternate embodiment, the nose piece will be rotatablerelative to the shaft. In either case, it will be necessary for the nosepiece to align the entry and exit ports of the return lumen to receivethe needle from the entry lumen and direct the needle to the exit lumen.

In another aspect of the device of the present invention, guide tubesare provided together with a mechanism to selectively extend the guidetubes across the tissue-receiving gap between the entry lumen and theentry port of the return lumen and between the exit port of the returnlumen and the exit lumen. The needle guide tubes help assure that theflexible needles will not become misaligned during passage throughtissue across the gap between the shaft and the nose piece.

In another particular aspect of the present invention, the devicefurther comprises a drive wheel on the shaft disposed to engage aflexible needle present in the entry lumen. In this way, even veryflexible needles (lacking substantial column strength) can be advancedthrough the entry lumen to the return lumen and subsequently to exitlumen. The present invention still further provides a suturing kitincluding a needle-guiding device, as described above, in combinationwith a flexible needle attached to a length of suture. The needle willhave a length sufficient to permit its introduction through the entrylumen, return lumen, and exit lumen, so that the needle may be advancedby pushing on the needle within the entry lumen until a distal end ofthe needle emerges from the exit lumen. In this way, a user can advancethe needle entirely through the needle-guiding path, and grasp theneedle once it is emerged from the exit lumen, either manually or usinghemostats. Preferably, the needle will be from 10 cm to 30 cm in length.The needle may then be withdrawn from the needle-guiding device and thesuture released from the device. After the device is withdrawn from thetissue tract, the suture may be tied off in a conventional manner.

The present invention further comprises kits including the needleguiding device, the needle, and suture. Conveniently, all threecomponents can be packaged together in sterile packaging, such as asterile flexible pouch.

The devices and methods of the present invention are useful wherever itis desired to place a tied suture loop to close a tissue puncture site,particularly a puncture site through the wall of a body lumen, and moreparticularly a percutaneous vascular puncture site at the distal end ofa tissue tract. The devices and methods can achieve closure whollywithin the tissue tract leading to a puncture site and can bemanipulated entirely from the portion of the device lying outside of thetissue tract. The present invention will find its greatest use in thesealing of a femoral artery cannulation site made in connection withpercutaneous transluminal procedures such as angiography, angioplasty,atherectomy, laser ablation, stent placement, intravascular drugdelivery, intravascular imaging, and the like. The present inventionwill also find use in other medical procedures which rely onpercutaneous access to hollow body organs and lumens, such aslaparoscopic procedures, endoscopic procedures, artheroscopicprocedures, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a suturing device constructed inaccordance with the principles of the present invention.

FIG. 1A illustrates a flexible suturing needle attached to a length ofsuture, which needle and suture may be introduced using the suturingdevice of FIG. 1.

FIG. 1B illustrates an alternative distal end configuration for thesuturing device of FIG. 1.

FIG. 2 is an elevational view of the suturing device of FIG. 1, withportions broken away.

FIG. 3 is a detailed view of the distal end of the suturing device ofFIG. 1, with portions broken away.

FIG. 3A is a cross-sectional view taken along line 3A--3A of FIG. 3.

FIG. 3B is a cross-sectional view taken along line 3B--3B of FIG. 3.

FIG. 4A is a detailed view similar to FIG. 3, illustrating the releaseof suture from the distal end of the device.

FIG. 4B is a cross-sectional detail of FIG. 4A illustrating asuture-release slot of the present invention.

FIGS. 5A-5C illustrate the suturing device in its initial configurationprior to extension of needle guide tubes and advancement of a suturingneedle.

FIGS. 6A-6C illustrate the suturing device in an intermediateconfiguration after the needle guide tubes have been advanced but priorto advancement of the suturing needle within the needle guide path.

FIGS. 7A-7C illustrate the suturing device with the needle guide tubesadvanced and the suturing needle partially advanced through the needleguide path by a needle drive wheel.

FIG. 8 is a detailed view illustrating the distal end of theneedle-guiding device placed within a puncture in the femoral arteryprior to advancement of the needle guide tubes.

FIGS. 9-12 illustrate successive steps of advancing the suturing needlewithin the needle-guide path of the needle-guiding device in detail.

FIG. 13 illustrates a tied suture loop applied by the device in themethod of the present invention.

FIGS. 14A-14C illustrate an alternative arrangement of the distal end ofthe needle-guiding device of the present invention, where a rotatablenose piece carrying a pair of return lumens is provided for receiving apair of needles from the guide shaft.

FIGS. 15A and 15B illustrate placement of single and double suture loopsusing the first and second embodiments of the present invention.

FIGS. 16A and 16B illustrate an alternative suture release mechanismwhere a portion of the nose piece slides to expose the return lumen.

FIGS. 17A and 17B illustrates a second alternative suture releasemechanism, where a portion of the nose piece swings open to expose thereturn lumen and release the suture.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Referring now to FIGS. 1-3, 3A, and 3B, a suture applying device 10which is suitable for suturing and sealing of a percutaneous vascularpuncture site, particularly punctures made to the femoral artery in apatient's groin, will be described. It will be appreciated, however,that the device of the present invention can be readily adapted for usewith punctures made to other hollow body organs and lumens, although itmay be necessary to modify the dimensions and other particular aspectsof the device to accommodate a different usage environment.

The suture applying device 10 of the present invention comprises anelongate shaft 12 having a nose piece 14 at its distal end and a handle16 at its proximal end. The shaft is illustrated as an elongatecylindrical rod having a plurality of axial lumens formed therein, butcould also comprise a variety of other geometries which are able tofulfill the essential requirements of the shaft, i.e., defining a needleguide path from its proximal end to its distal end and again back fromthe distal end to the proximal end. The shaft will usually also includeor otherwise define a guide wire lumen (particularly for vascularapplications), and a blood pressure detection lumen. Each of theseaspects will be described in more detail with regard to the exemplaryembodiment of FIGS. 1-3.

Shaft 12 includes a needle entry lumen 18 terminating at a needle exitport 20 at its distal end and a needle exit lumen 22 which begins with aneedle entry port 24 at its distal end. The shaft 12 further includes aguide wire lumen 26 which extends through the nose piece 14 and a bloodpressure detection lumen 28 having a blood inlet port 30 at its distalend. The blood inlet port 30 is located within a transition(gap-defining) region 32 between the nose piece 14 and shaft 12, as willbe described in more detail hereinafter.

The nose piece 14 includes a needle return lumen 36 which is preferablya U-shaped lumen having a needle entry port 38 aligned with needle exitport 20 of the needle entry lumen 18 and a needle exit port 40 alignedwith needle entry port 24 of the needle exit lumen 22. In this way, aflexible needle 42 (FIGS. 1A and 3) entering through the entry lumen 18will be able to pass across the gap defined by the transition region 32and into the needle return lumen 36 (in some cases through a needleguide tube as described in connection with FIG. 3 hereinafter) where itsdirection of travel will be reversed from the distal direction to theproximal direction. The needle 42 will then emerge from the needle exitport 40 of return lumen 36 and be able to enter the needle exit lumen 22through aligned needle entry port 24. Thus, tissue disposed intransition region 32, i.e., the gap between the distal end of shaft 12and the proximal end of nose piece 14, will be penetrated by theflexible needle 42 on opposite sides of a puncture site, as will bedescribed in greater detail hereinafter.

In the suturing of a puncture site in the wall of a body lumen, and inparticular the wall of a blood vessel, it is desirable to minimize andpreferably eliminate any tearing or enlarging of the puncture during thesuturing procedure. With the device of the present invention, however,it will also be desirable to distend the periphery of the puncture sothat its edges are extended along an axis transverse to that of theblood vessel. In this way, opposed edges of the puncture will be exposedto the needle as it passes through the transition region 32 between thenose piece 14 and the shaft 12. In order to simultaneously achieve boththese objectives, i.e., distending the edges of the puncture withouttearing, and further provide a nose piece 14 having sufficient size tospace the entry and exit ports of the return lumen 36 sufficiently farapart to be aligned with needle ports 20 and 24, the geometry of thenose piece 14 and of the transition region 32 are selected to properlyconfigure and conform the edges of the luminal puncture as the sutureapplying device 10 is introduced therethrough.

In particular, the nose piece 14 will be tapered from a small-diameter,generally circular distal tip 50 to a proximal portion or length 52having a generally oval configuration, as best illustrated in FIGS. 3and 3A. In the illustrated embodiment, the nose piece 14 is generallyconical until a circular junction 53 is reached. The proximal portion 52of the tip makes a transition from a circular cross-section at 53 to anoval cross-section at 55. The particular dimensions of the tip will beselected based on the intended use of the device 10. For the suturingand sealing of the femoral artery, the distal tip 50 will typically havea diameter from about 0.25 mm to 1 mm, typically being just large enoughto receive the guide wire GW into the guide wire lumen 26. The maximumdimensions of the oval-shaped proximal portion at 55 will be in therange from 2 mm to 4.5 mm (major diameter) and in the range from 1 mm to2.25 mm (minor diameter). In particular the major diameter will beselected to permit the needle entry port 38 to be sufficientlyspaced-apart from the needle exit port 40 to provide a desired distancebetween the entry and exit penetrations of the suturing needle throughthe tissue surrounding the luminal puncture. The oval cross-section ofthe proximal end 55 of the proximal portion 52 is thus desirable sinceit minimizes the total peripheral length about the nose piece which mustpass through the luminal wall puncture while maximizing the distancebetween the entry port 38 and exit port 40, as just described. In thisway, proper spacing of the needle passages through the tissue will beprovided with minimum stretching or enlargement of the luminalpenetration.

The geometry of the transition region 32 will also be chosen to providefor proper manipulation and positioning of the tissue surrounding theluminal puncture site with minimum distending (and preferably notearing) of the edges of the puncture site. In the embodiment of FIGS.1-3, the transition region 32 will conform at its distal end to the ovalshape of the proximal end 55 of the proximal portion 52 of nose piece14. The cross-sectional orientation of the transition region 32 changesin the proximal direction, eventually becoming an oval 57 having itsmajor axis disposed orthogonally (i.e. at 90°) relative to the majoraxis of the proximal portion 52 of nose piece 14 (FIG. 3B). The ovalcross-section of the transition region 32 will rotate 90° from theposition at 55 to the position at 57. That is, the peripheral shape anddistance will remain constant, but the orientation of the major axiswill turn through 90° over the axial length of the transition region. Bymaintaining a constant total peripheral length around the transitionregion at all points (e.g., equal to the outer diameter of theintroducer sheath which had been used in performing the intravascularprocedure and removed prior to suturing), the luminal penetration isheld firmly and turned to the desired orientation without furtherdistending or tearing.

An alternative nose piece 15 configuration for the suturing device 10 isillustrated in FIG. 1B. The nose piece 15 comprises a tapered distal tip51, a generally cylindrical shank portion 53, and a proximal portion 55A(which is similar to the proximal portion 52 of the previousembodiment). A needle return lumen 59 is formed in the proximal portion55A and is generally identical to the lumen 42 described above. The nosepiece 15 will be longer than the nose piece 14, typically having alength in the range from 15 cm to 30 cm, usually about 20 cm. Thepurpose of the longer nose piece 15 is to allow the suturing device 10to be partially withdrawn from the luminal puncture. By partiallywithdrawing the device 10, the suture can be released from the nosepiece, and the suture partly tightened prior to total withdrawal of thedevice. In this way, the puncture can be at least partly closed by thesuture prior to removal of the device, and hemostasis can be maintainedto limit blood loss prior to complete closure of the puncture.

Usually, both the tapered distal tip 51 and the shank 53 will havecircular cross-sections, with the peripheral length of the shank beinguniform along its length and generally equal to the maximum peripherallength of the nose piece, usually having a diameter equal to that of theintroducer sheath which had previously been in place in the puncture.The proximal end portion 55 serves as a transition from the circularperipheral shape of the shank 53 to an oval transition region 59, whichwill generally be identical to the transition region 32 in device 10.

The remaining description herein will refer specifically to devices 10having the nose piece 14 illustrated in FIGS. 1, 2, 3, et seq, but itwill be appreciated that such description applies as well to devicesincorporating nose piece 15.

The suturing needle 42 and attached suture 62 are illustrated in detailin FIG. 1A. Suturing needle 42 will be formed from a highly flexiblematerial which will be able to pass through the radius of return lumen36. Typically, the turn radius will be in the range from about 1 mm to2.25 mm, and the needle 42 will have to be able to pass through thisradius without undergoing substantial permanent (non-elastic)deformation which would cause binding or jamming as the needle passesoutward from the return lumen 42. Preferably, the needle 42 will beformed from stainless spring steel or a superelastic material, typicallynickel titanium alloy. Preferred superelastic nickel titanium alloys areavailable commercially from suppliers, such as Shape MemoryApplications, Sunnyvale, Calif., Innovative Technologies International,Beltsville, Md. and Fort Wayne Metals, Fort Wayne, Ind. The diameter ofthe needle will typically be from about 0.2 mm to 0.5 mm, and the lengthwill be sufficient to permit the needle to be advanced through the entrylumen 18, across the return lumen 36, and outward through the exit lumen20, while the needle is being pushed from a location at or near theproximal end of the entry lumen. Typically, the needle will have alength in the range from about 10 cm to 30 cm, preferably in the rangefrom about 15 cm to 20 cm. The needle will be attached to a length ofsuture, typically from about 50 cm to 100 cm, usually at the proximalend of the needle. Particular methods for forming needles and attachingneedles to suture are well known in the art.

Referring now to FIGS. 4A and 4B, in a preferred embodiment of thepresent invention, suture 62 (FIG. 1A) will be released from the nosepiece 14 through a suture-release slot 60. The needle return lumen 36 innose piece 14 will have a diameter which is large enough to receive theflexible needle 42 with a clearance in the range from 0.03 mm to 0.1 mm.The width of the suture-release slot 60, however, will be less than thediameter of the flexible needle 42, typically from 0.1 mm to 0.35 mm. Inthis way, the needle will travel through the return lumen 36 and willnot be able to escape through the suture-release slot 60. Suture 62which is attached to the butt end of the flexible needle 42 will besufficiently small to pass through the suture-release slot 60. Thus,after the needle 42 has passed entirely through the needle return lumen36 and into the needle exit lumen 22 in shaft 12, the suture 62 willpass out of the nose piece 14 through the suture release slot 60, asillustrated in steps (1), (2), and (3) in FIG. 4A. The suture 62 willthus directly engage the posterior side of the tissue to be sutured,leaving the nose piece 14 free to be withdrawn through the luminalpuncture without entanglement with the suture 62. FIG. 4B illustrates aproximal or trailing end 64 of the flexible needle 62 as it passesthrough the needle return lumen 36. As can be seen, the suture 62 passesinto the suture-release slot 60 as it is drawn through the return lumen36 by the needle 42. Alternative suture-release mechanisms will bedescribed in connection with FIGS. 16A, 16B, 17A, and 17B, hereinafter.

In a preferred aspect of the present invention, the nose piece 14 willinclude a soft tip 66 to facilitate entry into the body lumen beingsutured. Conveniently, the soft tip 66 can be formed from a softpolymer, such as a polyether block amide, e.g., Pebax®. The soft tip 66can be joined to the more rigid proximal portion of the nose piece 14 byany conventional manner. In all other ways, the soft tip can form acontinuous structure with the proximal portion of the nose piece 14. Theproximal portion of nose piece 14, the transition region 32, and theshaft 12, will typically be formed from a relatively rigid polymer(e.g., polycarbonate) or a metal (e.g., stainless steel) by conventionalmethodologies, such as extrusion, molding, machining and the like. Thedifferent portions of the device may be formed in separate pieces, andjoined later, e.g. by the use of adhesives, heat bonding, mechanicalattachment, or the like.

Referring now to FIGS. 1, 2, and 5A-5C, a needle guide and advancementmechanism constructed in accordance with the principles of the presentinvention will be described. The needle guide and advancement mechanismincludes an entry guide tube 70 and an exit guide tube 72, each beingsecured at its proximal end in a guide tube yoke 74. The guide tubes 70and 72 are slidably received in the needle entry lumen 18 and needleexit lumen 22, respectively, so that axial translation of the guide tubeyoke 74 (as described hereinafter) can advance the distal ends of theguide tubes across the gap defined by the transition region 32 (asillustrated in FIG. 3 and described in more detail in connection withFIGS. 6A-6C). The guide tube yoke 74, in turn, is slidably mounted in aspring retainer 76, with a spring 78 being disposed therebetween. Asillustrated in FIGS. 5A and 5B, spring 78 is in compression, with theentire assembly of the guide tubes 70 and 72 and guide tube yoke 74being in a retracted configuration, i.e. fully to the left in FIGS. 5Aand 5B.

A yoke-release mechanism comprises a thumb lever 80 extending fromhandle 16 and a latch member 82 which captures the guide tube yoke 74through an extension 84. The thumb lever 80 and latch member 82 arepivotally mounted within the handle and are operatively connectedthrough a pin and slot 86 so that depression of thumb lever 80 in thedirection of arrow 88 will release the guide tube yoke extension 84, asillustrated in FIGS. 6A-6C. In this way, spring 80 will decompress totranslate the guide tube yoke 74 distally, i.e. toward the right, asillustrated in FIGS. 6A-6C.

The entry guide tube 70 will carry the flexible suture needle 42 with asharpened distal tip 90 projecting just out of the distal end of thetube, as illustrated in FIGS. 5A and 5C. In this way, the needle 42 willfill the lumen of the guide tube 70 and prevent tissue from entering thelumen as the guide tube is advanced. The exit guide tube 72 will have astylet 92 (or other obturator) filling its axial lumen. As illustratedin FIGS. 5A and 5C, the stylet 92 will preferably also have a sharpeneddistal tip 94 which projects outwardly from the distal end of the guidetube as the guide tube is advanced. The purpose of the stylet 92 is toprevent tissue from entering (and blocking) lumen of guide tube 72 as itis advanced through the tissue. After the exit guide tube 72 has beenadvanced across the transition region 32, the stylet 92 will bewithdrawn leaving the lumen of the guide tube open and available foradvancement and passage of the flexible needle 42, as will be describedin greater detail in connection with FIGS. 7A-7C.

Referring now in particular to FIGS. 1, 2, and 5A-5C, the exemplaryneedle guide and advancement mechanism for use with the device of thepresent invention further comprises a drive wheel 100 rotatably mountedin yoke 102. The yoke 102, in turn, is attached to the interior ofhandle 16 on a spring mount 104. Spring mount 104 urges the drive wheel100 against flexible suture needle 42 in a manner described more fullyin connection with FIGS. 6A-6C. Preferably, the periphery 106 of thedrive wheel 100 is serrated or otherwise roughened to enhance frictionalcoupling between the drive wheel and the needle 42 to facilitateadvancement.

Drive wheel 100 is driven by a rack 110 which engages pinion gear 112which is coaxially mounted and attached to the drive wheel. The rack110, in turn, is actuated by a lever 114 which is pivotally attached tothe handle 16. A mechanism (not illustrated) will usually be providedfor biasing the rack 110 against the pinion gear 112. For example, aleaf spring could be provided within the yoke to upwardly bias the rack110 against the pinion gear 110. Alternatively, a torsion spring couldbe provided at the pivot 116 connecting the rack 110 to the lever 114.

The drive wheel 100 is actuated by manually squeezing the lever 114toward the handle 16 in the direction of arrow 118. It will be possibleto select the relative diameters of the drive wheel 100 and the piniongear 112 and the length and pivot point of the rack so that a singlestroke of the lever 114 can fully drive the needle through the targettissue, return lumen 36, and needle exit lumen 22, so that the needlecan be manually grasped or mechanically captured, e.g., using hemostats,as it emerges from the exit lumen. Alternatively, a mechanism (notillustrated) could be provided to permit multiple, sequential actuationof the lever 114 in order to drive the needle the requisite distance.

The suture applier 10 is illustrated in its "shelf" configuration inFIGS. 2 and 5A-5C. That is, the needle guide tubes 70 and 72 are fullyretracted, i.e. drawn to the left in each of these figures. Bydepressing thumb lever 80, the user releases the guide tube yoke 74,thus driving the guide tubes in the distal direction as indicated byarrows 120 in FIG. 6A. Such movement of the entry guide tube 70 alignsan elongate cutout 122 in the guide tube with the periphery of drivewheel 100, as best illustrated in FIG. 6B. In this way, the drive wheel100 directly engages the side of the suture needle 42 which is exposedthrough the cutout 122. At this moment, the guide tubes will also extendacross the transition region 32 and seat into the return lumen 36 in thenose piece 14. The stylet 92 may then be withdrawn in order to open thelumen of the exit guide tube 72 so that it is free to receive the sutureneedle.

After the stylet 92 is withdrawn, the needle 42 may be advanced by theneedle advance mechanism, as illustrated in FIGS. 7A-7C. The lever 114is manually closed in the direction of arrow 130 to translate rack 110across the pinion gear 112. This motion causes drive wheel 100 to rotateclockwise in the direction of arrow 132. As the drive wheel 100 isengaging suture needle 42 through the cutout 122, the needle will bemoved in the distal direction (arrow 134) causing the sharpened tip 90to advance and cross the gap defined by transition region (arrow 136),through the return lumen 36 and back through the transition region gap(arrow 138). The needle advancement mechanism will be actuatedsufficiently (or for a sufficient number of times) to advance the needle42 so that its distal end 90 emerges from the proximal end of the device10, as illustrated in broken line in FIG. 7A. The needle may then begrasped or captured and withdrawn from the device 10 in order to drawthe suture through the device and the tissue to be sutured, as will bedescribed in more detail hereinafter.

It would also be possible to modify the drive wheel 100 advancemechanism to engage and advance the guide tube 70 so that the guide tubecould be advanced by an initial portion of the stroke of lever 114.Guide tube 70 could be coupled to guide tube 72 through a yoke similarto the yoke 74, but no spring 78 or yoke-release mechanism would berequired. A variety of particular mechanisms for advancing the guidetubes and/or needles would be available within the scope of the presentinvention.

Referring now to FIGS. 8-13, use of the device 10 for applying end tyinga suture loop in a blood vessel BV wall will be described in detail.Referring in particular to FIG. 8, the device 10 is introduced throughan existing tissue tract T, typically formed by an introducer sheathwhich has been previously placed in connection with a conventionalintravascular therapeutic or diagnostic procedure, such as angiography,angioplasty, atherectomy, laser ablation, cardiac mapping, cardiacablation, or the like. The introducer sheath is removed prior tointroduction of the nose piece 14 of the suturing device 10. Asdiscussed above, the maximum peripheral length of the nose piece 14 willgenerally be the same as the circumferential length of the introducersheath so that the penetration is not torn but remains blocked oroccluded by the device to reduce blood loss.

The device 10 is introduced with the needle guide tubes 70 and 72 fullyretracted in the proximal direction and with the stylet 92 in place inthe lumen of the exit guide tube 72. The device 10 is positioned overthe previously placed guide wire GW and introduced sufficiently so thatthe gap defined by the transition region 32 receives the edges of thepuncture P. Conveniently, proper positioning of the device 10 can beconfirmed by detecting the flow of blood into blood inlet port 30 and asit appears at the open proximal end of lumen 28.

After the device 10 has been properly positioned, as illustrated in FIG.8, the needle guide tubes 70 and 72 will be advanced across the gapdefined by the transition region 32, as illustrated in FIG. 9. Theneedle advancement mechanism, as previously described, will be used toeffect the advance. Each guide tube 70 and 72 will pass through tissuewhich is located within the transition region 32. The presence of theflexible needle 42 in guide tube 70 prevents "coring" of the tissue intothe guide tube 70. Similarly, the presence of stylet 92 in needle guidetube 72 prevents such coring.

The stylet 92 is next withdrawn, leaving the lumen of the needle guidetube 72 empty and available to receive flexible needle 42, asillustrated in FIG. 10.

The flexible needle 42 is next advanced across the U-shaped return lumen36 and into the needle return guide 72, as illustrated in FIG. 11. Notethat the highly flexible nature of the needle together with the closefit between the needle, guide tubes 70 and 72, and return lumen 32,permits it to turn across the small radius and advance with buckling inspite of the frictional and bending forces opposing the needle'sadvance. The needle continues to be advanced until the sharpened distaltip 90 emerges from the device 10 (as illustrated previously in FIG.7A). After it emerges, the needle tip 90 may be grasped and pulledthrough the device 10, drawing the suture 62 through the return lumen36. The needle guide tubes 70 and 72 will be withdrawn, permitting thesuture to be drawn outward from the nose piece through thesuture-release slot 60, as illustrated in FIGS. 4A-4B and 12 (where theouter portion of slot 60 is shown broken away). After the suture hasbeen released from the nose piece 14, the device 10 may be partially ortotally withdrawn, leaving the suture accessible for tying of a knot Kto close the puncture wound, as illustrated in FIG. 13.

When using a device 10 having an elongated nose piece 15, as illustratedin FIG. 1B, it will be preferred to only partially withdraw the deviceso that the shank portion 53 remains within the penetration P. As theshank 53 will preferably have a perimeter substantially equal to that ofthe introducer sheath previously in place, the shank will be able toocclude the puncture to inhibit blood loss, without distending thepuncture. The extra length provided by shank 53 permits the nose piece15 to be withdrawn sufficiently to release the suture 62 while stilloccluding the penetration P. The knot K can thus be tied and partiallytightened prior to total withdrawal of the device 10, allowing veryrapid closure of the penetration by tightening the suture.

Referring now to FIGS. 14A-14C an alternative embodiment of a nose piece200 is illustrated. Nose piece 200 is mounted on an axial rod 202 whichpermits it to be rotated between an aligned position, as illustrated inFIG. 14B, and a transverse position, as illustrated in FIGS. 14A and14C. When in the aligned position of FIG. 14B, the nose piece has anoval cross-section which gradually increases in size and which forms asmooth and continuous surface with the transition region 204,facilitating introduction of the device through a tissue puncture. Theperipheral length of the oval section is matched with the circumferenceof the introducer sheath used in the initial interventional ordiagnostic procedure to minimize distending of the tissue around theluminal puncture site. In the configuration of FIG. 14B, the returnlumens 208 and 210, however, are out of rotational alignment with theneedle entry lumens 212 and 214 and needle exit lumens 216 and 218.Therefore, prior to needle advancement, the needle entry and exit lumenswill be properly aligned with the needle return lumens in the nose piece200 by rotating the nose piece 200 by 90° to the position of FIGS. 14Aand 14C. The nose piece 200 will then be rotated back to the alignedconfiguration of FIG. 14B after suture release from the nose piece 200and prior to withdrawal of the device from the tissue tract.

As can be seen in FIGS. 15A and 15B, the embodiment of FIGS. 1-7 can beused to form a single suture loop where the nose piece 14 has arelatively small peripheral length (as illustrated on the right-handhalf of each figure). The embodiment of FIGS. 14A-14C is particularlyuseful for forming pairs of suture loops, as illustrated on theleft-hand side of each of FIGS. 15A and 15B. Of course, the embodimentof FIGS. 1-7 could be readily adapted to place two suturessimultaneously, while the nose cone of FIGS. 14A-14C could be modifiedto place only a single suture.

Referring now to FIGS. 16A and 16B, a first alternative suture releasemechanism is illustrated. A nose piece 300 includes a sliding cover 302which may be moved from the covered configuration (FIG. 16A) to theuncovered configuration (FIG. 16B) by sliding the cover proximally, asillustrated by arrow 304. When the cover is moved proximally, returnlumen 308 is exposed, permitting the suture 62 to exit from the lumen,as illustrated by arrows 310.

A second suture release mechanism is illustrated in FIGS. 17A and 17B.The mechanism is similar to that illustrated in connection with FIGS.16A and 16B, except that cover 400 on nose piece 402 is pivotallyattached to open as illustrated in FIG. 17B. Suture 62 can thus bereleased from the return lumen 404, as illustrated by the arrows 406.

Although the foregoing invention has been described in detail forpurposes of clarity of understanding, it will be obvious that certainmodifications may be practiced within the scope of the appended claims.

What is claimed is:
 1. A suturing device comprising:a shaft having aproximal end, a distal end, an entry lumen, and an exit lumen; and anose piece attached to the distal end of the shaft and having a returnlumen disposed to receive a flexible needle from the entry lumen and toturn the needle to enter the exit lumen, wherein the nose piece isaxially spaced-apart from the distal end of the shaft to define a gapbetween the shaft and a proximal end of the nose piece receives tissueto be sutured.
 2. A suturing device as in claim 1, further comprising atransition region having a generally oval cross-section scanning the gapbetween the shaft and the nose piece.
 3. A suturing device as in claim2, where the nose piece is tapered with an oval cross-section over atleast a portion of its proximal length, wherein the maximum peripheraldistance around the nose piece at its proximal end is generally equal tothat around the transition region.
 4. A suturing device as in claim 3,wherein the nose piece comprises a tapered distal tip, a shank portionhaving a cylindrical cross-section with a circumference generally equalto the maximum peripheral length, and a proximal end piece which changesto an oval cross-section having a constant peripheral length generallyequal to the maximum peripheral length.
 5. A suturing device as in claim3, wherein the nose piece is fixed relative to the shaft.
 6. A suturingdevice as in claim 3, further comprising means for rotating the nosepiece relative to the shaft and transition region.
 7. A suturing deviceas in claim 1, further comprising needle guide tubes disposed in theentry and exit lumens and means to extend the guide tubes across the gapand to the return lumen in the nose piece.
 8. A suturing device as inclaim 1, further comprising a drive wheel disposed on the shaft toengage a flexible needle present in the entry lumen, whereby rotation ofthe drive wheel advances the needle through the entry lumen, across thegap, through the return lumen, across the gap, and through the exitlumen.
 9. A suturing device as in claim 1, wherein the nose piece has asuture-release slot formed contiguously with the return lumen.
 10. Asuturing device as in claim 1, further comprising means for opening thenose piece to release suture therefrom.
 11. A suturing device as inclaim 10, wherein the opening means slides a portion of the nose pieceto expose the return lumen.
 12. A suturing device as in claim 10,wherein the opening means swings a portion of the nose piece to exposethe return lumen.
 13. A suturing device comprising:a shaft having aproximal end and a distal end; and means on the shaft for defining aneedle path having an entry segment, a return segment, and an exitsegment, wherein the entry and exit segments are separated from thereturn segment by a circumferential gap which receives tissue to besutured.
 14. A suturing device as in claim 13, further comprising meanson the shaft for advancing a needle through the needle path.
 15. Asuturing device as in claim 13, further comprising means for extendingneedle guide tubes across the gap between the entry segment and thereturn segment and between the return segment and the exit segment. 16.A suturing device as in claim 13, wherein the shaft includes a bodyportion, a transition region, and a nose piece, wherein the entry andexit segments of the needle path comprise lumens within the bodyportion, the return segment comprises a U-shaped lumen within the nosepiece, and the transition region defines the gap.
 17. A suturing deviceas in claim 16, wherein the nose piece is fixed relative to the bodyportion and wherein the nose piece and transition region have similarbut orthogonally disposed oval cross-sections.
 18. A suturing device asin claim 16, further comprising means for rotating the nose piece abouta longitudinal axis relative to the body portion.
 19. A method forsuturing a puncture site in a blood vessel wall at the distal end of atissue tract, said method comprising:positioning a needle-guiding devicethrough the tissue tract so that a nose piece of the device lies withinthe puncture site, wherein the nose piece has an annular gap whichoccludes blood flow from the blood vessel; and drawing a single locationon a single length of suture through the nose piece and across thepuncture site to close the puncture site.
 20. A suturing devicecomprising:a shaft having a proximal end, a distal end, an entry lumen,and an exit lumen; and a nose piece attached to the distal end of theshaft and having a return lumen disposed to receive a flexible needlefrom the entry lumen and to turn the needle to enter the exit lumen,wherein a gap between the shaft and a proximal end of the nose piecereceives tissue to be sutured; and a transition region disposed in thegap and having a generally oval cross-section.
 21. A suturing device asin claim 20, where the nose piece is tapered with an oval cross-sectionover at least a portion of its proximal length, wherein the maximumperipheral distance around the nose piece at its proximal end isgenerally equal to that around the transition region.
 22. A suturingdevice as in claim 21, wherein the nose piece comprises a tapered distaltip, a shank portion having a cylindrical cross-section with acircumference generally equal to the maximum peripheral length, and aproximal end piece which changes to an oval cross-section having aconstant peripheral length generally equal to the maximum peripherallength.
 23. A suturing device as in claim 21, wherein the nose piece isfixed relative to the shaft.
 24. A suturing device as in claim 21,further comprising means for rotating the nose piece relative to theshaft and transition region.
 25. A suturing device as in claim 20,further comprising needle guide tubes disposed in the entry and exitlumens and means to extend the guide tubes across the gap and to thereturn lumen in the nose piece.
 26. A suturing device as in claim 20,further comprising a drive wheel disposed on the shaft to engage aflexible needle present in the entry lumen, whereby rotation of thedrive wheel advances the needle through the entry lumen, across the gap,through the return lumen, across the gap, and through the exit lumen.27. A suturing device as in claim 20, wherein the nose piece has asuture-release slot formed contiguously with the return lumen.
 28. Asuturing device as in claim 20, further comprising means for opening thenose piece to release suture therefrom.
 29. A suturing device as inclaim 28, wherein the opening means slides a portion of the nose pieceto expose the return lumen.
 30. A suturing device as in claim 28,wherein the opening means swings a portion of the nose piece to exposethe return lumen.
 31. A suturing device comprising:a shaft having aproximal end, a distal end, an entry lumen, and an exit lumen; a nosepiece attached to the distal end of the shaft and having a return lumendisposed to receive a flexible needle from the entry lumen and to turnthe needle to enter the exit lumen, wherein a gap between the shaft anda proximal end of the nose piece receives tissue to be sutured; andmeans for opening the nose piece to release suture therefrom.
 32. Asuturing device as in claim 31, wherein the gap between the shaft andthe nose piece is defined by a transition region having a generally ovalcross-section.
 33. A suturing device as in claim 32, where the nosepiece is tapered with an oval cross-section over at least a portion ofits proximal length, wherein the maximum peripheral distance around thenose piece at its proximal end is generally equal to that around thetransition region.
 34. A suturing device as in claim 33, wherein thenose piece comprises a tapered distal tip, a shank portion having acylindrical cross-section with a circumference generally equal lo themaximum peripheral length, and a proximal end piece which changes to anoval cross-section having a constant peripheral length generally equalto the maximum peripheral length.
 35. A suturing device as in claim 33,wherein the nose piece is fixed relative to the shaft.
 36. A suturingdevice as in claim 33, further comprising means for rotating the nosepiece relative to the shaft and transition region.
 37. A suturing deviceas in claim 31, further comprising needle guide tubes disposed in theentry and exit lumens and means to extend the guide tubes across the gapand to the return lumen in the nose piece.
 38. A suturing device as inclaim 31, further comprising a drive wheel disposed on the shaft toengage a flexible needle present in the entry lumen, whereby rotation ofthe drive wheel advances the needle through the entry lumen, across thegap, through the return lumen, across the gap, and through the exitlumen.
 39. A suturing device as in claim 31, wherein the nose piece hasa suture-release slot formed contiguously with the return lumen.
 40. Asuturing device as in claim 31, wherein the opening means slides aportion of the nose piece to expose the return lumen.
 41. A suturingdevice as in claim 31, wherein the opening means swings a portion of thenose piece to expose the return lumen.
 42. A suturing devicecomprising:a shaft having a proximal end, a distal end, an entry lumen,and an exit lumen; a nose piece attached to the distal end of the shaftand having a return lumen disposed to receive a flexible needle from theentry lumen and to turn the needle to enter the exit lumen, wherein agap between the shaft and a proximal end of the nose piece receivestissue to be sutured; and at least one needle guide tube reciprocatablymounted in the shaft to extend from one of the entry and exit lumens tothe aligned opening of the return lumen in the nose piece.
 43. Asuturing device as in claim 42, further comprising a transition regionhaving a generally oval cross-section spanning the gap between the shaftand the nose piece.
 44. A suturing device as in claim 43, where the nosepiece is tapered with an oval cross-section over at least a portion ofits proximal length, wherein the maximum peripheral distance around thenose piece at its proximal end is generally equal to that around thetransition region.
 45. A suturing device as in claim 44, wherein thenose piece comprises a tapered distal tip, a shank portion having acylindrical cross-section with a circumference generally equal to themaximum peripheral length, and a proximal end piece which changes to anoval cross-section having a constant peripheral length generally equalto the maximum peripheral length.
 46. A suturing device as in claim 44,wherein the nose piece is fixed relative to the shaft.
 47. A suturingdevice as in claim 44, further comprising means for rotating the nosepiece relative to the shaft and transition region.
 48. A suturing deviceas in claim 42, further comprising a drive wheel disposed on the shaftto engage a flexible needle present in the entry lumen, whereby rotationof the drive wheel advances the needle through the entry lumen, acrossthe gap, through the return lumen, across the gap, and through the exitlumen.
 49. A suturing device as in claim 42, wherein the nose piece hasa suture-release slot formed contiguously with the return lumen.
 50. Asuturing device as in claim 42, further comprising means for opening thenose piece to release suture therefrom.
 51. A suturing device as inclaim 50, wherein the opening means slides a portion of the nose pieceto expose the return lumen.
 52. A suturing device as in claim 50,wherein the opening means swings a portion of the nose piece to exposethe return lumen.
 53. A suturing device comprising:a shaft having aproximal end and a distal end; and means on the shaft for defining aneedle path having an entry segment, a return segment, and an exitsegment, wherein the entry and exit segments each have one end at theproximal end of the shaft and are separated from the return segment by agap which receives tissue to be sutured.
 54. A suturing device as inclaim 53, further comprising means on the shaft for advancing a needlethrough the needle path.
 55. A suturing device as in claim 53, furthercomprising means for extending needle guide tubes across the gap betweenthe entry segment and the return segment and between the return segmentand the exit segment.
 56. A suturing device as in claim 53, wherein theshaft includes a body portion, a transition region, and a nose piece,wherein the entry and exit segments of the needle path comprise lumenswithin the body portion, the return segment comprises a U-shaped lumenwithin the nose piece, and the transition region defines the gap.
 57. Asuturing device as in claim 56, wherein the nose piece is fixed relativeto the body portion and wherein the nose piece and transition regionhave similar but orthogonally disposed oval cross-sections.
 58. Asuturing device as in claim 56, further comprising means for rotatingthe nose piece about a longitudinal axis relative to the body portion.59. A suturing device comprising:a shaft having a proximal end, a distalend, a body portion, a transition region, and a nose piece, wherein theentry and exit segments of the needle path comprise lumens extendingaxially over substantially the entire length of the body portion, thereturn segment comprises a U-shaped lumen within the nose piece, and thetransition region defines the gap; and means on the shaft for defining aneedle path having an entry segment, a return segment, and an exitsegment, wherein the entry and exit segments are separated from thereturn segment by a gap which receives tissue to be sutured, wherein thenose piece and transition region have similar but orthogonally disposedoval cross-sections.
 60. A suturing device as in claim 59, furthercomprising means on the shaft for advancing a needle through the needlepath.
 61. A suturing device as in claim 57, further comprising means forextending needle guide tubes across the gap between the entry segmentand the return segment and between the return segment and the exitsegment.
 62. A suturing device as in claim 59, wherein the nose piece isfixed relative to the body portion.
 63. A suturing device as in claim59, further comprising means for rotating the nose piece about alongitudinal axis relative to the body portion.